A definitive cause of tumors fibroids is unknown, but they appear to be related to estrogen. This relationship between fibroids and estrogen is known because tumors grow when taking birth control pills containing estrogen and during pregnancy when more hormones are released. Following menopause, when estrogen is no longer produced, tumors tend to shrink and even disappear.
Fibroid tumors may cause problems for women who wish to get pregnant because the tumors may be growing all along the uterine wall making implantation of a fertilized egg doubtful. Tumors fibroid may also cause some women to experience pelvic pain and heavy bleeding.
